Control for mechanical transmission

ABSTRACT

A manual shift transmission having multiple input and output portions is provided with a control having input and output shift rails. A laterally movable control shaft extends axially through cutouts in respective shift rails and carries cams adapted to cooperate with cam follower surfaces on corresponding cutouts to effect rectilinear movement of the shift rails upon rotation of the control shaft. The cams are arranged on the shaft so that the shaft may be positioned to place respective cams in register with the input and output shift rails while all other cams are out of register with the rail cutouts. The shift movement of respective output and input shift rails is overlapped during the rotation of the control shaft to decrease the throw of the shift lever.

CROSS REFERENCES

U.S. patent applications filed simultaneously herewith, one in the nameof Theodore A. Malott entitled "Lost Motion Transmission Control Cams",Ser. No. 229402, filed Jan. 29, 1981, and the other in the names ofTheodore A. Malott and Robert W. Wolfe entitled "Biased TransmissionControl Shaft", Ser. No. 230718, filed Jan. 29, 1981, both assigned tothe Assignee of the present invention.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The field of art to which this invention pertains includes shiftcontroly systems for multiple input-multiple output transmissions whichprovide a plurality of speed ratios in response to the movement of anoperator's shift lever or the like.

2. Description of the Prior Art

U.S. Pat. No. 4,000,662 assigned to the Assignee of the presentinvention discloses a similar gear train as disclosed herein. U.S. Pat.No. 4,068,537 also assigned to the Assignee of the present inventiondiscloses a sophisticated shift control system of the preselector orsemi-automatic type wherein shifts between drive ratios are made inresponse to the movement of an operator's shift lever and the release ofthe torque on the drive train.

A manual shift control system is jointly disclosed in U.S. Pat. Nos.4,155,271, 4,170,148 and 4,197,760, all assigned to the Assignee of thepresent invention, utilizing input and output control shafts. Thecontrol shafts are rotatable in response to shift lever movement. Aninterlock system is disclosed which prevents simultaneous rotation ofinput and output control shafts to thus prevent the overlapping of inputand output shift rail movement. Each cam shaft included one-way andtwo-way cams of the initial shift without overtravel type selectivelycapable of cooperation with input and output shift rails. The resultantincreased throw of the shift lever to accomplish a change in speedratios in the above-discussed manual control system requires arelatively large operating area for the shift lever.

Also disclosed in prior art transmission control systems are screwdriven control shafts having cams mounted thereon as shown in UnitedKingdom Pat. No. 1,306,117 and U.S. Pat. No. 3,429,194. Although theabove-discussed screw driven control shaft type of transmission issomewhat more simplified in design, one disadvantage is that theoperator is unable to bypass a speed ratio during speed changes.

Other prior art transmissions of interest to the present invention areU.S. Pat. Nos. 1,118,389, 1,229,301, 1,928,782, 2,812,667, 2,853,889,3,431,791, 3,487,713 and 3,857,299.

SUMMARY OF THE INVENTION

The present invention provides a single control shaft that is laterallymovable and rotatable in response to movement of a shift lever and alsoallows bypassing of speed ratios during speed changes when desired.Moreover, input and output shift rail movement is overlapped during achange of speed ratios to reduce the throw of the shift lever.

The transmission control system includes input and output shift rails.Each of the shift rails is provided with a centrally located cutout inalignment with one another so that the control shaft can be axiallypassed therethrough. The control shaft carries a plurality of one-waycams and bi-directional cams. The cams and interlocking members arearranged on the control shaft so that one of the cams is positioned inthe cutout of a selected input shift rail and another of the cam membersis positioned in the cutout of a selected output shift rail. The cammember positioned in the selected input shift rail is adapted tocooperate with the cam follower surface on the cutout of the selectedinput shift rail to effect rectilinear movement of the respective inputshift rail upon rotation of the control shaft in a chosen direction sothat the input portion of a speed ratio is selected. Similarly, theselected output cam member is adapted to cooperate with the cam followersurface of the selected output shift rail to effect rectilinear movementof the selected output shift rail upon rotation of the control shaft ina chosen direction so that the output portion of the speed ratio is alsoselected. In the first embodiment the movement of the output shift railis commenced before and terminated during the movement of the inputshift rail so that the movement of the input and output shift rails isoverlapped.

Further features and advantages of this invention will be more readilyunderstood by persons skilled in the art when following the detaileddescription in conjunction with the several drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a vertical cross-sectional view of a multiple input-multipleoutput nine speed transmission illustrating the first embodiment of theshift control system of the present invention;

FIG. 2 is a schematic illustration of the power paths through thetransmission in each of the possible forward and reverse speeds for thetransmission shown in FIG. 1;

FIG. 3 is a plan view of the transmission shown in FIG. 1 with the shiftlever broken away;

FIG. 4 is a vertical cross-sectional view looking in the direction ofarrows 4--4 in FIG. 3 with the shift control system of the FIG. 1transmission positioned in a neutral position between the fourth andfifth gears;

FIG. 5 is an enlarged cross-sectional view looking in the direction ofarrows 5--5 in FIG. 3 of the shift control system for the transmissionshown in FIG. 1;

FIG. 6 is a diagrammatic view of the output and input rail movementduring a change in speed ratio for the shift control system of the firstembodiment;

FIG. 7 is a schematic illustration of a transmission shift pattern forthe first embodiment;

FIG. 8 is a detail view of an interlock disc shown operating in a shiftrail cutout having a generally cross-like configuration;

FIGS. 9A-E is a detail view illustrating sequential cam movement of arearward directional R₂ cam with initial delay shown operating in amodified cross-like cutout;

FIGS. 10A-E is a detail view illustrating cam movement of a rearwarddirectional R₁ cam with overtravel shown operating in a FIG. 8 type railcutout;

FIGS. 11A-E is a detail view illustrating sequential cam movement of abi-directional S₁ cam with overtravel having a downwardly disposedactuator portion shown operating in a FIG. 8 type rail cutout;

FIGS. 12A-E is a detail view illustrating sequential cam movement of abi-directional O₂ cam with initial delay having an upwardly disposedactuator portion shown operating in a generally circular rail cutouthaving top cam follower portions;

FIGS. 13A-E is a detail view illustrating sequential cam movement of abi-directional O₁ cam with overtravel having an upwardly disposedactuator portion shown operating in a FIG. 8 type rail cutout;

FIGS. 14A-E is a detail view illustrating sequential cam movement of aforward directional F₁ cam with overtravel shown operating in a FIG. 8type cutout;

FIG. 15 is a cross-sectional view similar to FIG. 5 of a secondembodiment of the present invention for a shift control system for aseven speed transmission;

FIG. 16 is a schematic drawing similar to FIG. 7 illustrating the shiftpattern for a seven speed transmission shift control system of FIG. 15;

FIG. 17 is a cross-sectional view similar to FIG. 5 of a shift controlsystem of a third embodiment of the present transmission for a six speedtransmission;

FIG. 18 is a schematic drawing similar to FIG. 7 illustrating the shiftpattern for a six speed transmission shift control system of FIG. 17;

FIGS. 19A-E is a detail view illustrating sequential cam movement of abi-directional S₂ cam with initial delay having a downwardly disposedactuator portion and shown operating in a generally circular rail cutouthaving bottom cam follower portions;

FIG. 20 is a cross-sectional view similar to FIG. 5 of a fourthembodiment of the present invention for a shift control system for afive speed transmission;

FIG. 21 is a schematic drawing similar to FIG. 7 illustrating the shiftpattern for a five speed transmission shift control system of FIG. 20;

FIGS. 22A-E is a detail view illustrating sequential cam movement of anF₂ cam with initial delay shown operating in a modified cross-like railcutout with the lower section deleted; and

FIGS. 23A-E illustrates sequential cam movement of an O₁ cam withovertravel of a slightly different configuration than that of FIG. 13having an upwardly disposed actuator portion in a generally circularrail cutout having top cam follower portions.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The Nine Speed Transmission

Referring now to the drawings in detail, the specific transmission 28shown in FIG. 1, which can be used with the transmission control systemof this invention, is generally the same as the transmissions shown inprior U.S. Pat. Nos. 4,000,662, 4,155,271, 4,170,148 and 4,197,760, allassigned to the Assignee of this invention. For ease of understanding,however, the structure and function of transmission 28, which has aplurality of constant-meash change speed gears, is described below.

Transmission 28 includes a casing or housing 32, an input shaft 37rotatably journalled therein and an output shaft 38 axially aligned withthe input shaft and rotatably journalled relative to the input shaft andcasing 32. A countershaft 30 is parallel to and vertically displacedbelow output shaft 38, while a dead shaft 34, parallel to countershaft30, is fixedly retained in aligned bosses or stub walls 36 in casing 32.

Shaft 37 has a gear 40 affixed thereto or integral therewith, with gear40 being in constant mesh with gear 42 rotatably journalled oncountershaft 30. A conventional dog clutch 44, incorporating a knownclutch lock to prevent jumping out of gear and a known synchronizer 45,is disposed on the hub of gear 42 and is arranged either to drivablyconnect gear 42 to countershaft 30 for conjoint rotation therewith, orto occupy a neutral position as shown in FIG. 1. A typical prior artsynchronizer device is disclosed in U.S. Pat. No. 2,667,955, assigned tothe Assignee of the present invention.

Input shaft tubular portion 33, which is adjacent the inner axial end ofgear 40, has either affixed thereto or integral therewith, one end of asleeve 48 that coaxially surrounds output shaft 38, with sleeve 48forming an extension of the input shaft.

Rotatably journalled on sleeve 48 is a gear 58 that is in constant meshwith a further gear 60 integral with or affixed to countershaft 30.Rotatably journalled on output shaft 38, adjacent to the inner end ofsleeve 48, is a gear 64 that is slightly larger in diameter than gear 58and in constant mesh with a gear 66 integral with or affixed tocountershaft 30. Another conventional clutch 68, such as a dog clutch,also incorporating a clutch lock and a known synchronizer 69, isdisposed on sleeve 48 between gears 58 and 64 and is arranged either todrivably connect gear 58 to sleeve 48, or to drivably connect gear 64 tosleeve 48, or to occupy a neutral position as shown in FIG. 1. Thus,basically, it is the function of clutch 68 to connect either of gears 58and 64 for conjoint rotation with input shaft 37 via sleeve 48. Gears40, 58 and 64, whose pitch circle diameters differ from one another in awell known manner are thus in constant mesh with gears 42, 60 and 66,respectively, with the utilization of clutches 44 and 68 thus providingthree separate inputs to countershaft 30. The portion of transmisssion28 described so far may be designated the "input" portion of thistransmission.

Also journalled for rotation on output shaft 38 are gears 70, 72 and 74whose pitch circle diameters differ from one another in a well knownmanner, with gears 70 and 74 being in constant mesh, respectively, withgears 76 and 78 affixed to or integral with countershaft 30. Gear 76,which has a greater axial extent than gear 70, is also in mesh with agear 82 affixed to or forming part of a tubular reverse-idler shaft 80which in turn is journalled for rotation on dead shaft 34. Gear 72 is inconstant mesh with a gear 84 which is affixed to or forms a part ofshaft 80.

A further conventional clutch 88, such as a dog clutch, and alsoincorporating a clutch lock and a known synchronizer device 90, isdisposed on output shaft 38, intermediate gears 64 and 70, and isarranged to drivably connect either of these two gears to shaft 38 or tooccupy a neutral position as shown in FIG. 1. A similar conventionalclutch 92, incorporating a clutch lock and a known synchronizer 94, isdisposed on output shaft 38, intermediate gears 72 and 74, and isarranged to drivably connect either of these gears to shaft 38 or tooccupy a neutral position as shown in FIG. 1.

Basically, gears 64, 70, 72 and 74, together with gears 66, 76, 82, 84and 78, may be described as constituting the "output" portion oftransmission 28. It should be noted that gears 64 and 66 can alternatelyfunction both as input and output gears, as will be explained in moredetail as this description progresses.

In operation, transmission 28 has nine forward speeds and as many asthree reverse speeds, although not all of the three reverse speeds needbe utilized. For example, only one reverse speed is utilized in theillustrated shift control system of the first embodiment. FIG. 2 is aschematic showing of the various power paths through transmission 28 ineach of the possible forward and reverse speeds. As best seen in FIGS. 1and 2, transmission 28 can be defined as having a first input viaconstant mesh gears 40 and 42, with the latter being adapted to becoupled to countershaft 30 via clutch 44, with countershaft 30 rotatingin a direction opposite to that of input shaft 37. A second input isprovided by constantly meshing gears 58 and 60, with the former beingadapted to be coupled to input sleeve 48 via the forward (towards theinput portion of the transmission) operative position of clutch 68,thereby causing the rotation of countershaft 30 in a direction oppositeto that of input shaft 37. Yet another or third input is provided byconstantly meshing gears 64 and 66, with the former being adapted to becoupled to input shaft sleeve 48 via the rearward (toward the outputportion of the transmission) operative position of clutch 68, therebyrotating countershaft 30 in a direction opposite that of input shaft 37.

A first forward output from transmission 28 can be defined by constantlymeshing gears 78 and 74, with the latter being adapted to be coupled tooutput shaft 38 via the rearward operative position of clutch 92,thereby rotating output shaft 38 in a direction opposite to that ofcountershaft 30. A second forward output is defined by constantlymeshing gears 76 and 70, with the latter being adapted to be coupled tooutput shaft 38 via the rearward operative position of clutch 88,thereby rotating output shaft 38 in a direction opposite to that ofcountershaft 30. Yet another or third forward output is defined byconstantly meshing gears 66 and 64, with the latter being adapted to bejoined to output shaft 38 via the forward operative position of clutch88, thereby again rotating output shaft 38 in a direction opposite tothat of countershaft 30.

A reverse output is provided by constantly meshing gears 84 and 72, withthe latter being adapted to be coupled to output shaft 38 via theforward operative position of clutch 92, thereby rotating output shaft38 in the same direction as countershaft 30 (and in a direction oppositethat of input shaft 37).

An analysis of FIG. 2 will show that by utilizing the first input(40,42) together with the first output (78,74) provides a first forwardspeed. Continuing the use of the first input but utilizing the second(76,70) or third (66,64) outputs will provide second or third forwardoutput speeds. The second input (58,60) together with the first outputprovides a fourth forward speed, whereas the third input (64,66) withthe first output provides a fifth forward speed. The second inputtogether with the second output provides a sixth forward speed whereasthe third input together with the second output provides a seventhforward speed. An eighth forward speed is provided by utilizing thesecond input together with the third output. The third input, which canalso be the third output, provides a ninth or direct forward drive byutilizing clutch 68 to couple one side of the hub of gear 64 to inputshaft sleeve 48 and by utilizing clutch 88 to couple the other side ofthe hub of gear 64 to output shaft 38.

Three reverse speeds are available by coupling any of the first, secondor third inputs to the reverse output (84,72). In the illustratedexample only the first input reverse speed is utilized.

Another way of defining the structure and function of transmission 28is, as best seen in FIG. 2, that the first input is utilized in thefirst, second and third speeds as well as the first speed in reverse.The second input is utilized for the fourth, sixth and eighth speedsforward as well as the second speed in reverse. The third input isutilized for the fifth, seventh and ninth speeds forward. The firstoutput is utilized for the first, fourth and fifth speeds forward,whereas the second output is utilized for the second, sixth and seventhspeeds forward. The third output is utilized for the third, eighth andninth speeds forward, while the reverse output is utilized for all ofthe possible reverse speeds.

A shift control system, generally designated by numeral 100 and bestseen in FIGS. 4 and 5, for manually selecting any of the available powerpaths through the transmission, includes four shift forks or selectorelements A, B, C and D. Shift forks B, C and D are rigidly attached torespective shift rails 107, 101 and 103 as will be explained in moredetail as this description progresses. Shift fork A (best seen in FIG.4) is pivotally connected at its midpoint 112 to casing 32 and has asocket portion 114 attached to a lug member 116 which is in turn isrigidly connected with shift rail 105. The lower end of shift fork Aoperatively engages clutch 44. Shift forks B, C and D operatively engageclutches 92, 88 and 68, respectively.

Shift control system 100 includes a control cover 118 whose controlcover housing 120 fits over transmission 28 and is secured totransmission housing 32 by bolts 110. Parallel shift rails 101, 103,105, and 107 are slidably supported in control cover housing 120, forrectilinear movement relative thereto, on support pads 122. Shift rails101 and 103 which are associated with shift forks C and D, respectively,may be denominated as the output shift rails since they serve to actuateoutput clutches 88 and 92, respectively. Similarly, shift rails 105 and107, which are associated with shift forks A and B, respectively, may bedenominated as the input shift rails since they serve to actuate inputclutches 44 and 68, respectively.

Since clutches 68, 88, and 92 have a neutral position and an operativeposition on either side of neutral, each one of respective shift rails107, 101 and 103 is provided with three notches 179 that can cooperatewith a respective spring loaded detent 180 in order to position therespective shift rail to any one of these positions. See shift rail 101illustrated in FIG. 4. Shift rail 105 is provided with only two notches179 since clutch 44 has one operative position in addition to itsneutral position.

Output shift rail 101 has a centrally located cutout 102 having agenerally cross-like configuration which is symmetrical about itsvertical and horizontal center lines. An identical cutout 104 isprovided in output shift rail 103. See FIGS. 10, 11, 13 and 14. In FIG.9 input shift rail 105 has a centrally located cutout located 106 havinga modified cross-like configuration symmetrical about its horizontalcenter line but not its vertical center line, see FIG. 12. Shift rail107 has a circular cutout 108 having a top cam follower portion 109,which will be discussed in detail below.

Control cover housing 120 is provided with a top cover portion 150having a general circular opening 152. Inserted in the opening 152 is acap member 154 having a partial spherical opening 156 that is adapted toreceive the mounting ball 188 of a shift lever 184. The mounting ball188 is supported by a Belleville spring 153. A pair of spaced apartopposed pins 198 project into the opening 156 in cap member 154 and arereceived in respective slots 187 of mounting ball 188 to provide shiftlever pivotal movement in the conventional manner. The cap member 154has an outwardly flared flange 158 to receive the peripheral edge 124 ofa closure member 126 which engages the shift lever 184 above the topcover portion 150. Closure member 126 is preferably made of a resilientmaterial that will accommodate movement of the shift lever 184 and actsas a lubricant seal.

A control shaft 128 is rotatably journalled in control cover 120 andretained in spaced apart opposed bearing caps 130 that are attached toor integral with control cover 120, best shown in FIG. 5.

The control shaft 128 is provided with a centrally located cup shapedrecess 132 which receives a lower shift lever assembly portion 185 ofshift lever 184. The shift lever assembly portion includes a lower shiftlever ball 186 received in a nylon annular bearing 189. The provision ofthe nylon annular bearing which abuts the outer surface of the cupshaped recess 132 reduces friction and vibration transmitted to theshift lever from the control shaft. Optionally, control cover housing120 could also be of nylon construction to reduce noise and vibration.

With reference to FIG. 7, upward or forward movement of the handle ofshift lever 184 will cause the control shaft 128 to rotate in acounterclockwise direction as viewed in FIGS. 8-14 through apredetermined arc, and downward longitudinal movement will cause thecontrol shaft 128 to rotate in a clockwise direction through anotherpredetermined arc. Additionally, lateral movement of the handle (notshown) of the shift lever in a leftward direction as viewed in FIG. 5will cause the control shaft 128 to move axially to the right andrightward movement of the shift lever handle will cause the controlshaft to move axially to the left.

A cylindrical projection 147 having an inner collar member 167 isinternally mounted in a recessed bore 151 in the right outer end ofcontrol shaft 128. The collar portion 167 is prevented from escaping thebore 151 by a retaining ring 169 mounted in an annular groove in thebore 151. The projection 147 is urged outwardly by a light blockoutspring 155. Similarly, a cylindrical projection 149 is mounted in arecessed bore 159 in the left outer end of control shaft 128 and has acollar portion 141 retained in the bore 159 by a retaining ring 173mounted in a groove in the bore 159. The projection 149 is urgedoutwardly by a light blockout spring 157 sandwiched between collarportion 141 and the inner end of bore 159.

A relatively wide interlocking member 140 mounted on the right end ofcontrol shaft 128 is a hollow cylinder having a heavy blockout spring175 mounted therein sandwiched between the interior surface of left sidewall 176 of interlocking member 140 and a collar member 177 slidablymounted around the control shaft 128 which is retained in the interiorof hollow interlocking member 140 by a retaining ring 178 mounted in agroove in the interior surface of interlocking member 140.

In FIG. 5 the control shaft 128 is in a neutral position between 4th and5th speed ratios (neutral position 133 as viewed in FIG. 7) so thatright projection 147 is in slight contact with the interior surface ofbearing cap 130. When the handle of the shift lever 184 is moved to itsneutral position between the 6th and 7th speed ratios (neutral position131 as viewed in FIG. 7) the control shaft 128 shifts to the left asviewed in FIG. 5 so that the outer end of cylindrical projection 149 isin slight contact with the interior surface of left bearing cap 130.Accordingly the fourth through seventh speeds may be considered to formthe standard "H" pattern of the transmission. To move the shift lever184 to a neutral position between the 8th and 9th speed ratios (neutralposition 139 as viewed in FIG. 7) the handle (not shown) of the controllever 184 is moved to the right as viewed in FIG. 7 so that the controlshaft 128 as viewed in FIG. 5 moves to the left so that light blockoutspring 157 is compressed. The neutral position between the 8th and 9thspeed ratios is reached when the light blockout spring 157 is fullycompressed. To place the transmission 28 in the 2nd or 3rd speed ratiosthe handle of the shift lever 184 is moved to a neutral position betweenthe 2nd and 3rd speed ratios (neutral position 135 as viewed in FIG. 7)so that the control shaft is moved to the right as viewed in FIG. 5 sothat light blockout spring 151 is further compressed from its FIG. 5position and heavy blockout spring 175 is not compressed further thanits FIG. 5 position. The transmission 28 is in a neutral positionbetween the first and reverse gears (neutral position 137 as viewed inFIG. 7) when extreme leftward movement of the shift lever handle asviewed in FIG. 7 occurs and in this condition both light blockout spring151 and heavy blockout spring 175 are fully compressed. The varyingresistance in the positioning of the handle of the shift lever 184enables the operator to determine his position in the shift pattern inthe expanded "H" shift pattern shown in FIG. 7.

The control shaft 128 is contained in the cutouts 106, 108, 102 and 104in the shift rails and carries a plurality of cam members whichselectively engage corresponding cam follower surfaces in the respectivecutouts to axially shift the respective rails when a camming memberundergoes rotation in a cutout due to longitudinal movement of the shiftlever 184. Each cam is keyed on the control shaft in the usual fashionand the cams are held in place on the control shaft by a respective nut171 threaded on either end of the outer surface of control shaft 128.

In FIG. 6 the input and output shift rail movement during a change inspeed ratios is diagrammatically illustrated. Also shown in FIG. 6 arethe neutral, first intermediate, second intermediate and final rotativepositions of the control shaft 128 which correspond to the initialposition of both shift rails, the beginning of input shift railmovement, the termination of output shift rail movement and thetermination of input shift rail movement, respectively.

In the shift I portion of the FIG. 6 diagram the selected cam associatedwith the output shift rail cutout (further discussed below is positionedin cutout 102 or 104 of respective output shift rail 101 or 103 forengagement with the cam follower surface of the cutout to shift theoutput shift rail in a chosen direction. Output shift rail movementcontrols the engagement of the corresponding output clutch in theconventional manner. Initial output shift rail movement causes theelimination of the clearances between the elements of the synchronizerand the conventional chamfered clutch teeth in the clutch in a knownfashion. Further illustrated output rail movement operates the selectedclutch to place the selected gears in driving engagement. The points ofengagement past clutch teeth chamfers and full clutch engagement areshown in FIG. 6. The output rail does not undergo substantial movementduring the latter portions of the control shaft 128 rotation since thecam positioned in the output rail cutout undergoes lost motion; i.e.,its cam surfaces are not engaged with the cam follower surfaces of thecutout during latter portions of rotation of control shaft 128.

In the shift II portion of the FIG. 6 diagram the movement for an inputshift rail such as input shift rail 105 or 107 is illustrated. Theselected cam associated with input shift rail cutout (further discussedbelow) is positioned in the cutout of the selected input shift rail andundergoes lost motion during the first portions of rotation of controlshaft 128. After a delay the first engagement between the cam positionedin the selected input shift rail and the camming surfaces of the inputshift rail cutout actuates the corresponding input clutch which operatesin the identical sequence as the output clutch discussed above. Thelatter portions of the output shift rail movement overlap with theinitial portions of the input shift rail movement. The overlap occurswhile the selected output clutch teeth are engaged at the point past thetooth chamfers to full engagement, while input shift rail movement iscausing the elimination of the clearances between the synchronizerelements and the input clutching teeth.

With further reference to FIG. 7, the selected output and input shiftrail is identified for each speed ratio. The arrows indicate thedirection of movement of the lower portion of each respective fork A, B,C, D and associated clutch 44, 92, 88 and 68. Since forks B, C and D areconnected rigidly to their respective shift rails 107, 101 and 103 theymove in the same direction as their shift rails. Shift fork A ispivotally connected to shift rail 105, hence the upper portion of fork Amoves in a direction opposite to its shift rail. The arrangement of camson the control shaft 128 is determined by the desired shift leverpattern, such as that shown in FIG. 7 and the design of the transmissionused therewith.

The two basic types of cam members mounted on the control shaft aredouble oscillating motion-single linear motion cams (unidirectionalcams) and double oscillating motion-double linear motion cams(bidirectional cams). All cam members are adapted to cooperate withtheir associated shift rails to effect shift rail movement when theshaft 128 and cam members thereon are rotated from a neutral rotativeposition to a final rotative position. The unidirectional cams used inthe present transmission 28 are denominated F cams and R cams. F camsare unidirectional cams which shift a corresponding shift rail in aforward direction towards the input portions of the transmissionregardless of the direction of shaft rotation. Similarly R cams areunidirectional cams which shift the corresponding shift rail in adirection toward the rearward output portions of the transmission.

The subnumeral "1" found in F₁ and R₁ cams indicates initial shift camswith overtravel, i.e., cams undergoing lost motion during the latterportions of the rotation of control shaft 128. The subnumeral "2" foundfor example in R₂ cams indicates a cam with a delayed shift. Each of thecams have return portions for returning the associated shift rail fromits shifted position back to its original position. The return portionsof each subnumeral "1" cam are of the delayed shift type, while the turnportions of each of the subnumeral "2" cams are of the initial shiftwith overtravel type. It should be noted that all subnumeral "1" camsare output cams in the illustrated first embodiment while all subnumeral"2" cams are input cams. Therefore the selected output shift rail isshifted before the input shift rail when going from a neutral positionto a speed ratio while the selected input shift rail is returned beforethe selected output shift rail when going from a speed ratio to aneutral position.

S cams are cams that shift the corresponding shift rail in the samedirection as the lower shift lever ball 186 during shift lever movement.O cams shift corresponding shift rails in the opposite direction of thelower ball 186 during shift lever movement.

From the above description, it can be noted that the letter andsubnumber of each cam will identify the type of cam (unidirectional orbidirectional) and the manner in which shift rail movement isaccomplished.

FIGS. 8-14 illustrate the cam member-shift rail cutout interactiontaking place during speed ratio changes in transmission 28. As an aid tounderstanding the invention, the different types of cam members inoperation with associated cutouts of selected shift rails illustrated inFIGS. 8-14 will be discussed in detail below.

FIG. 8 illustrates a circular interlock disc member 138 positioned inthe cutout 102 of input shift rail 101. The interlock member 138 duringrotation of shaft 128 prevents the aligned shift rail 101 from beingdisplaced since the outer peripheral surface of interlock member 138 isin abutment with outer corner portions 123 of the cam follower surfaceof the respective cutout. Similarly, interlock member 146 may bepositioned in cutout 104 of output shift rail 103. Interlock membersappear also in FIG. 5. As illustrated in FIG. 5 control shaft 128 alsoincludes similar wide interlocking cylindrical members 140 and 148disposed on opposite ends of control shaft 128 which are receivable inselected cutouts and operate in identical fashion as the interlockmember 138 discussed above. In addition, interlocking surfaces 166 and170 respectively, are machined on the control shaft 128 on either sideof cup shaped recess 132 and also serve to lock associated shift railsduring a speed ratio change in transmission 28.

FIGS. 9A-E illustrates an R₂ cam operating in cutout 106 of shift rail105. FIG. 9C illustrates the position of the R₂ cam when the controlshaft 128 is in its neutral position. The R₂ cam has top and bottomtooth portions 163 which are inclined away from right end wall portions111 of cutout 106 when the control shaft 128 and R₂ cam mounted thereonis in its neutral FIG. 9C position. The clockwise movement of the R₂ camfrom a FIG. 9C to a FIG. 9E position is accomplished by moving thehandle of the shift lever in a downward longitudinal direction as shownin FIG. 7. Under clockwise rotation of the control shaft 128, the toptooth portion 163 comes in contact with top end wall 111 of the cutoutcam follower surface as shown in FIG. 9D and further clockwise rotationof control shaft 128 will cause shift rail 105 to move in a rearwarddirection which because of the intervening lever moves clutch 44forwardly. In FIG. 9E the control shaft has been rotated until thebackside of lower tooth portion 163 abuts tooth locking portion 113 ofthe cam follower surface of cutout 106 and an upper corner portion 115of the cam follower surface of cutout 106 is received in an upper notchreturn portion 117 of the R₂ cam. In the FIG. 9E position the controlshaft is prevented from further clockwise rotational movement which issensed by the operator manipulating shift lever 184 to indicate that theshift is completed. To change speed ratios the R₂ cam is rotatedcounterclockwise from the FIG. 9E position so that the upper notchreturn portion 117 in abutment with the upper corner portion 115 of camfollower surface of the cutout 106 will shift the shift rail 105 towardsthe forward input direction of the transmission 28 to return the shiftrail to its FIG. 9D position then overtravel to return the control shaftto its FIG. 9C position. At this point the control shaft can be axiallyrepositioned or further upward longitudinal movement of the shift lever184 as shown in FIG. 7 will effect additional counterclockwise rotationof control shaft 128 to cause the lower tooth portion 163 of the R₂ camto be placed in abutment with the lower end wall 111 of the cam followersurface of cutout 106 and further counterclockwise rotation of controlshaft 128 will cause shift rail 105 to shift in a rearward directionuntil the R R₂ cam is in the FIG. 9A position wherein the backside ofupper tooth 163 is received in upper locking portion 113 of the outercam follower surface at cutout 106 and lower corner portion 115 isreceived in lower notch return portion 117 of the R₂ cam. This movesrail 105 in a rearward output direction to move clutch 44 forwardly thesame as previously described for cam movement between FIG. 9C and FIG.9E. Then downward movement of the shift lever 184 to a neutral positionof the shift lever as shown in FIG. 7 will cause the R₂ cam to shift theshift rail 105 back to its neutral 9C position from its 9A position dueto contact between notch return portion 117 and locking surface 113.

In FIGS. 10A-E an R₁ cam operates in a cutout 102 or 104 to shift theshift rail 101 or 103 in a rearward output direction. The R₁ cam hasupper and lower tooth portions 119 adjacent to upper and lower right endwall portions 121 of the cam follower surface of cutout 102 when thecontrol shaft 128 is in its neutral position as shown in FIG. 10C.Movement of the shift lever 184 in a downward direction as viewed inFIG. 7 will cause the control shaft 128 to rotate in a clockwisedirection so that the R₁ cam shifts the shift rail 101 in a rearwardoutput direction until the cam-rail contact is disengaged due to the tipof the upper tooth 119 clearing the end wall 121 of the outer camfollower surface of cutout 102 as shown in FIG. 10D. Further lost motionclockwise rotation of the control shaft 128 will result in the R₁ cambeing positioned in the 10E position wherein middle locking portion 144of the R₁ cam is in contact with the right lower corner portion 123 ofthe outer cam follower surface of cutout 102 and the backside of lowertooth portion 119 is in contact with lower left end wall 121. To returnthe shift rail 101 or 103 to its neutral position, the control shaft isrotated in a counterclockwise direction wherein a trailing upper edgereturn portion 125 after an initial lost motion delay will come incontact with left upper end wall 121 to shift the shift rail 101 or 103in a forward input direction until both the shift rail and the controlshaft are returned to their FIG. 10C position. At this point the controlshaft can either be axially repositioned or continued upwardlongitudinal movement of the control lever 184 as viewed in FIG. 7 willcause the control shaft 128 to continue to rotate in a counterclockwisedirection such that lower tooth portion 119 adjacent to right lower endwall 121 will move the shift rail 101 or 103 in a rearward outputdirection until the tip of the lower tooth portion 119 passes by theright lower corner 123 of cutout 102 or 104. The operator of the shiftlever 184 can feel that the shift is completed when the backside of theupper tooth 119 is in contact with left upper end wall 121 and thelocking portion 144 is in contact with the right upper corner portion123 of cutout 101 or 103. To return the R₁ cam from its FIG. 10Aposition to its FIG. 10C position, lower trailing edge return portion125 after initial lost motion delay will come in contact with left lowerend wall 121 to shift the shift rail 101 or 103 forward to its FIG. 10Cneutral position.

In FIGS. 11A-E an S₁ cam is positioned in cutout 102 of shift rail 101.The S₁ cam has a wide actuator portion 127 receivable in the bottomcross portion 129 of the outer cam follower surface of cutout 102. Theneutral position for the S₁ cam is shown in FIG. 11C so that the S₁ camis vertically disposed and the outer surfaces of the actuator portion127 are adjacent to respective lower end walls 121 forming the lowercross portion 129. Clockwise rotation of control shaft 128 will causethe left edge of actuator portion 127 to press against the lower leftend wall 121 of cutout 102 to cause the shift rail 101 to move in aforward input direction until the actuator portion 127 clears the lowerleft outer corner 123 of cutout 102 as shown in FIG. 11D. Furtherclockwise lost motion rotation will place the S₁ cam in FIG. 11Eposition where the S₁ cam is locked from further rotation since an upperleft stop portion 161 is in contact with right upper corner portion 123of cutout 102 and the central portion of the lower edge of actuatorportion 127 is in contact with the left lower corner 123 of cutout 102.To return the output shift rail 101 to its neutral FIG. 11C position,the S₁ cam is rotated in a counterclockwise position so that the rightstop portion 161 of actuator portion 127 becomes a return portion andafter an initial post motion delay is in contact with lower right endwall 121 to shift the shift rail 101 or 103 in a rearward direction toreturn it to its FIG. 11C position. Continued counterclockwise rotationof the control shaft 128 and the S₁ cam mounted thereon will move theshift rail 101 or 103 from its FIG. 11C neutral position in a rearwardoutput position until the S₁ cam is in the position shown in FIG. 11B sothat the leading right edge of actuator portion 127 of the S₁ cam clearsthe lower right corner 123 of the cutout 102 or 104. Further lost motionrotation of the S₁ cam in a counterclockwise position will causerightward locking portion 161 of the S₁ cam to contact the upper leftcorner 123 of cutout 102. Return of the S₁ cam from the FIG. 11Aposition to the FIG. 11C neutral position is simply the reverse of theabove-described process.

In FIGS. 12A-E an O₂ cam is positioned in the cutout 108 of the shiftrail 107. When the O₂ cam is in its neutral FIG. 12C position a singletooth portion 190 of the O₂ cam is spaced from the end walls 143 of atop cam follower surface 109 of cutout 108. Under clockwise rotation ofcontrol shaft 128 the O₂ cam moves from its FIG. 12C neutral position toits FIG. 12D position wherein initial contact is made between the toothportion 190 and right end wall 143. Further clockwise rotation ofcontrol shaft 128 shifts the shift rail 107 in a rearward outputdirection until left locking notch-return portion 142 on the O₂ cam isin contact with the left corner surface 145 of top cam follower surface109.

Counterclockwise rotation of control shaft 128 and the O₂ cam mountedthereon from the FIG. 12E position forwardly shifts the input shift rail107 by the left locking notch-return portion 142 pressing against leftcorner 145 of cutout 108 until the notch clears the left corner 145 asshown in FIG. 12D. Further lost motion counterclockwise rotation of theO₂ cam returns it to the FIG. 12C position, where the control shaft 128may be axially repositioned or rotated further in a counterclockwisedirection so that tooth portion 190 abuts left end wall 143. Furthercounterclockwise rotation of the O₂ cam in cutout 108 from the FIG. 12Bposition to the FIG. 12A position effects the forward shifting of inputshift rail 107. The shift is completed when right locking notch-returnportion 142 contacts the right corner 145 of the cam follower surface109.

The O₁ cam of FIGS. 13A-E is identical to the S₁ cam of FIGS. 11A-Eexcept that the position of the actuator portion 127 is verticallyreversed in the shift rail 101 or 103 and operates in the top crossportion 129. Clockwise rotation of the control shaft 128 now effectsrearward movement of the shift rail 101 or 103 and counterclockwiserotation of the control shaft effects forward movement of the shift rail101 or 103. Otherwise the operation of the O₁ cam of FIGS. 13A-E isidentical to the operation of the S₁ cam in FIGS. 11A-E and likereference numerals are utilized for identical parts.

An F₁ cam is positioned in cutout 102 or 104 of rail 101 or 103 as shownin FIGS. 14A-E. The F₁ cam is a horizontally reversed R₁ cam of FIGS.10A-E and its upper tooth portion 119 shifts the shift rail 101 or 103in a forward input direction upon rotation of control shaft 128 ineither a clockwise or counterclockwise direction. The reference numeralsused in FIG. 10 to identify the R₁ cam are also repeated in FIG. 14 foridentical parts. Otherwise the operation and function of the F₁ cam isidentical to that of the R₁ cam.

Operation of Nine Speed Transmission

In FIG. 5 the control shaft 128 is in a neutral position between thefourth and fifth speed ratios so that an O₂ cam 134 is positioned in thecutout 108 of input shift rail 107 and a R₁ cam 136 is positioned in thecutout 104 of output shift rail 103. Additionally, interlock member 138is positioned in cutout 102 of output shift rail 101 and relatively widecylindrical interlocking member 140 is in cutout 106 of input shift rail105. When the handle of shift lever 184 is moved upwardly to its FIG. 7fourth speed ratio position, the control shaft 128 is rocked or rotatedin a counterclockwise direction so that R₁ cam 136 rotates from itsneutral FIG. 10C position through its FIG. 10B position to its FIG. 10Aposition so that output shift rail 103 and fork D are shifted in arearward direction to actuate clutch 92 to place gears 74 and 78 inoperation to provide the fourth speed ratio output. Additionally, O₂ cam134 rotates from its neutral FIG. 12C position through its FIG. 12Bposition to its FIG. 12A position so that input shift rail 107 and forkB are shifted in a forward direction to actuate clutch 68 to place gears58 and 60 in operation to provide the fourth speed ratio input. Tochange speed ratios, the handle of the shift lever 184 is returned toits neutral position 133 shown in FIG. 7 between the fourth and fifthspeed ratios causing these selected shift rails and forks to return totheir corresponding neutral positions.

To place the transmission 28 in its fifth speed ratio, the shift leverhandle is moved from its neutral position 133 downwardly to itsindicated fifth speed ratio position shown in FIG. 7. The R₁ cam 136rotates from its FIG. 10C position through its FIG. 10D position to itsFIG. 10E position so that output shift rail 103 and fork D are moved ina rearward direction to actuate clutch 92 to place gears 74 and 78 inmating engagement to provide the fifth speed ratio output. Additionally,O₂ cam 134 rotates from its neutral FIG. 12C position through its FIG.12D position to its FIG. 12E position to shift both the output shiftrail 101 and fork B in a rearward direction to actuate clutch 68 toplace gears 64 and 66 in operation to provide the fifth speed ratioinput.

As viewed in FIG. 7 to shift the transmission 28 from the neutralposition 133 between the fourth and fifth speed ratios to a neutralposition 135 between the second and third speed ratios, the shift leverhandle is pivoted to the left so that the control shaft 128 moves onecam to the right as viewed in FIG. 5 to place S₁ cam 160 in the cutout102 of output shift rail 101 and R₂ cam 162 in the cutout 106 of inputshift rail 105. When the shift lever handle is in the neutral position135, wide interlocking member 148 is in the cutout 108 of input shiftrail 107 and interlock disc 146 is in cutout 104 of output shift rail103.

When the shift lever handle is moved upwardly to its FIG. 7 second speedratio position, the control shaft 128 rotates in a counterclockwisedirection causing S₁ cam 160 to rotate from its neutral FIG. 11Cposition through its FIG. 11B to its FIG. 11A position so that outputshift rail 101 and fork C are shifted in a rearward direction to actuateclutch 88 to place gears 76 and 70 in operation to provide the secondspeed output in the second speed ratio. Additionally, R₂ cam 162 rotatesfrom its neutral FIG. 9C position through its FIG. 9B position to itsFIG. 9A position so that input shift rail 105 is shifted in a rearwarddirection. However, due to the conventional pivotable connection of forkA to the housing 32 at the midpoint 112 of fork A, the lower end of forkA is shifted in a forward direction to actuate clutch 44 to place gears40 and 42 in operation to provide the second speed ratio input. Tochange speed ratios, the shift lever handle is returned to its neutralposition 135 causing the selected shift rails and forks to return totheir corresponding neutral positions.

As viewed in FIG. 7, to place the transmission 28 in its third speedratio, the handle of the shift lever 184 is moved from its neutralposition 135 downwardly to its indicated third speed ratio position. TheS₁ cam 160 rotates from its FIG. 11C position through its FIG. 11Bposition to its FIG. 11A position so that output shift rail 101 and forkC are moved in a forward direction to actuate clutch 88 to place gears64 and 66 in operation to provide the third speed ratio output.Additionally, R₂ cam 162 rotates from its neutral FIG. 9C positionthrough its FIG. 9B position to its FIG. 9A position to shift inputshift rail 105 and fork A to actuate clutch 44 to place gears 40 and 42in operation to provide the third speed ratio input.

As shown in FIG. 7, to place the transmission 28 in first or reversespeed ratios, the handle of the shift lever 184 is positioned at neutralposition 137 so that the control shaft 128 is shifted two cams to theright as viewed in FIG. 5 to position R₂ cam 196 in cutout 106 of inputshift rail 105 and O₁ cam 164 in cutout 104 of output shift rail 103.Additonally, relatively wide interlocking member 148 is still positionedin cutout 108 of input shift rail 107 and interlocking surface 166 ispositioned in output shift rail 101.

When the handle of the shift lever 184 is moved upwardly to its reversespeed ratio position as shown in FIG. 7, the control shaft 128 isrotated in a counterclockwise direction so that O₁ cam 164 rotates fromits neutral FIG. 13C position through its FIG. 13B position to its FIG.13A position so that output shift rail 103 and fork D are shifted in aforward direction to actuate clutch 92 to place gears 72 and 84 inoperation to provide the reverse speed ratio output. Additionally, R₂cam 196 operates in an indentical fashion as R₂ cam 162 as described inthe description of the second speed ratio. To change speed ratios, thehandle of the shift lever 184 is returned to its neutral position 137between the reverse and first speed ratios.

As shown in FIG. 7, to place the transmission 28 in its first speedratio, the handle of the shift lever 184 is moved from its neutralposition 137 downwardly to its indicated first speed ratio position. TheO₁ cam 164 rotates from its neutral FIG. 13C position through its FIG.13D position to its FIG. 13E position so that output shift rail 103 andfork D are shifted in a rearward direction to actuate clutch 92 to placegears 74 and 78 in operation to provide the first speed ratio output.Additionally, R₂ cam 196 operates in identical fashion as R₂ cam 162 asdescribed in the third speed ratio input to provide the first speedratio input.

As shown in FIG. 7, to place the transmission 28 in its sixth or seventhspeed ratios, the handle of shift lever 184 is moved to the neutralposition 131 to shift the control shaft 128 one cam position to the leftof that shown in FIG. 5 so that R₁ 183 is positioned in cutout 102 ofoutput shift rail 101 and O₂ cam 168 is positioned to cutout 108 ofinput shift rail 107. Additionally, interlocking surface 170 ispositioned in cutout 104 of output shift rail 103 and relatively wideinterlocking member 140 is positioned in cutout 106 of input shift rail105.

When the handle of shift lever 184 is moved upwardly to its FIG. 7,sixth speed ratio position, the control shaft 128 and R₁ cam 183 mountedthereon rotates in a counterclockwise direction to rearwardly shiftoutput shift rail 101 and fork C to actuate clutch 88 to place gears 70and 76 in operation to provide the sixth speed ratio output. R₁ cam 183functioning in the identical manner as R₁ cam 136 in cutout 104 ofoutput shift rail 103 operates in the fourth speed ratio outputdescribed above. Additionally, O₂ cam 168 in cutout 108 of shift rail107 provides the sixth speed ratio input in an identical fashion as O₂cam 134 as described in the description of the fourth speed ratio inputdiscussed above.

To place the transmission 28 in its seventh speed ratio, the handle ofthe shift lever 184 is moved from its neutral position 137 downwardly toits indicated seventh speed ratio position. R₁ cam 183 in cutout 102 ofoutput shift rail 101 provides the seventh speed ratio output to actuateclutch 88 to place gears 70 and 76 in operation in an identical fashionas discussed above for the sixth speed ratio. Additionally, O₂ cam 168in cutout 108 of input shift rail 107 operates in an identical fashionas O₂ cam 134 in cutout 108 of input shift rail 107 in the fifth speedratio input as discussed above.

As shown in FIG. 7, to place the transmission 28 in the eighth or ninthspeed ratios, the handle of the gear shift selector 184 is moved to theneutral position 139 so that the control shaft 128 is moved two cams tothe left as shown in FIG. 5 so that O₂ cam 172 is positioned in cutout108 of input shift rail 107 and F₁ cam 174 is positioned in cutout 102of output shift rail 101. Additionally, locking surface 170 of controlshaft 128 is positioned in cutout 104 of output shift rail 103 andrelatively wide interlocking member 140 is positioned in cutout 106 ofinput shift rail 105.

When the handle of the shift lever 184 is moved upwardly to its FIG. 7eighth speed ratio position, the control shaft 128 rotates in acounterclockwise direction so that F₁ cam 174 mounted thereon moves fromits neutral FIG. 14C position through its FIG. 14B position to its FIG.14A position so that output shift rail 101 and fork C are shifted in aforward direction to actuate clutch 88 to place gears 64 and 66 inoperation. Additionally, O₂ cam 172 operates to provide the eighth speedinput in an identical fashion as the fourth speed ratio input isprovided by O₂ cam 134 discussed above.

To place the transmission 28 in its ninth speed ratio, the handle of theshift lever 184 is moved from its neutral position 139 downwardly to itsindicated ninth speed ratio position shown in FIG. 7. The F₁ cam 162rotates from its FIG. 14C position through its FIG. 14D position to itsFIG. 14E position so that output shift rail 101 and fork C are shiftedto actuate clutch 88 in a forward direction. Additionally, the O₂ cam172 operates in the same fashion as described above for O₂ cam 134 inthe description of the fifth speed ratio input to actuate clutch 68 inthe rearward output direction. The effect of these operations is to lockthe input and output shafts together for direct drive, through sleeve48, clutch 68, gear 64 and clutch 88.

To summarize, the selected cams and interlocks are positioned in thecutouts of the respective shift rails to provide the speed ratios asfollows:

    ______________________________________                                        Speed Input Shift                                                                              Input Shift                                                                             Output Shift                                                                           Output Shift                              Ratio Rail 105   Rail 107  Rail 101 Rail 103                                  ______________________________________                                        R-1   R.sub.2 Cam 196                                                                          Wide Inter-                                                                             Interlocking                                                                           O.sub.1 Cam 164                                            locking   Surface 166                                                         Member                                                                        148                                                          2-3   R.sub.2 Cam 162                                                                          Wide Inter-                                                                             S.sub.1 Cam 160                                                                        Interlocking                                               locking            Member 146                                                 Member                                                                        148                                                          4-5   Wide Inter-                                                                              O.sub.2 Cam                                                                             Interlocking                                                                           R.sub.1 Cam 136                                 locking    134       Member 138                                               Member 140                                                              6-7   Wide Inter-                                                                              O.sub.2 Cam                                                                             R.sub.1 Cam 183                                                                        Interlocking                                    locking    168                Surface 170                                     Member 140                                                              8-9   Wide Inter-                                                                              O.sub.2 Cam                                                                             F.sub.1 Cam 174                                                                        Interlocking                                    locking    172                Surface 170                                     Member 140                                                              ______________________________________                                    

The Seven Speed Transmission

Referring now to FIGS. 15 and 16, a second embodiment of the presentinvention is illustrated and is essentially identical to the firstembodiment of FIGS. 1-14 except that the fourth and fifth speed ratiosare eliminated so that a seven speed transmission is provided. Likecomponents are denoted by the same reference numerals as in FIGS. 1-14except that 100 series numerals are expressed as 200 series numerals.

The modifications to transmission 28 shown in FIG. 1 necessary toaccommodate the control system 200 shown in FIG. 15 are not set forth indetail since such modifications would be obvious to one skilled in theart. In the control system shown in FIG. 15, O₂ cam 134 and interlockmember 138 used in the fourth and fifth speed ratios in the firstembodiment are eliminated. An additional interlocking member 2246 ismounted on the control shaft 228 adjacent the leftward portion ofcup-shaped recess 232 and operates in the cutout of shift rail 203 whenthe control shaft 228 is positioned in the second or third speed ratiosor the neutral position 235 between the second and third speed ratios asviewed in FIG. 16.

The direction of movement of the lower portion of each selected fork isshown in FIG. 16. It should be noted that the reverse through thirdspeed ratios shown in FIG. 16 are identical to that shown in FIG. 7while the fourth through seventh speed ratios in FIG. 16 are identicalto the sixth through ninth speed ratios shown in FIG. 7.

The recessed bore 159 of control shaft 128 and the parts mounted thereinshown in FIG. 5 of the first embodiment are eliminated in the secondembodiment since the elimination of the fourth and fifth speed ratios ofthe first embodiment renders light blockout spring 157 unnecessary.

The Six Speed Transmission

Referring now to FIGS. 17-19, a third embodiment of the presenttransmission is shown and is similar to the first embodiment of thecontrol system except as discussed below. Accordingly, like componentsare denoted as in FIGS. 1-14 except that they are expressed in 300series notation.

In the third embodiment a transmission control system 300 for a sixspeed transmission is disclosed that has two reverse speeds, R1 and R2(optional). A multiple input-multiple output transmission for thecontrol system of the third embodiment is not illustrated but a knownconventional transmission could easily be adapted to cooperate with thistransmission control system.

The transmission control system 300 includes output shift rails 3301 and303 and input shift rail 3307. Forks B, C, and D are associated with therespective shift rails as in the first embodiment. It should be notedthat pivotally mounted fork A is not included in the third embodiment soall the forks move in the same direction as their respective rails areillustrated in FIG. 18. The cutout for rail 3301 has a bottom camfollower portion 3309 similar to the cutout 108 of shift rail 107 in thefirst embodiment. The input rail 3307 has a cutout similar to cutout 102or 104 of output shift rails 101 or 103 of the first embodiment. Thecutout for the output shift rail 303 is identical to cutout 104 ofoutput shift rail 103 of the first embodiment.

S₂ cams 381-382 are utilized in this embodiment as illustrated in FIG.19. S₂ cam 381 is positioned in cutout 3302 of shift rail 3301 duringthe third and fourth speed ratios and S₂ cam 382 during the fifth andsixth speed ratios. The cutout 3302 has a bottom cam follower portion3309 capable of receiving tooth portion 3390 of each S₂ cam.

In its neutral FIG. 19C position, the actuator portion 3390 of the S₂cam positioned in the cutout 3302 is spaced from the end walls 3343 ofthe cam follower surface on the cutout 3302. Under clockwise rotation ofcontrol shaft 328, each S₂ cam moves from its neutral FIG. 12C positionto its FIG. 12D position wherein initial contact is made between theactuator portion 3390 and left end wall 3343. Further clockwise rotationof the control shaft 328 shifts the shift rail 3301 in a forward inputdirection until right locking notch-return portion 3342 on cam O₂ is incontact with the right corner surface 3345 of lower cam follower surface3309.

Counterclockwise rotation of control shaft 328 and the S₂ cam mountedthereon from the FIG. 19E position forwardly shifts the output shiftrail 3301 by means of the left locking notch-return portion 3342pressing against left corner 3345 of cutout 3302 until the notch clearsthe left corner 3345 as shown in FIG. 19D. Further lost motioncounterclockwise rotation of the S₂ cam returns it to the FIG. 19Cposition where the control shaft 328 may be axially repositioned orrotated further in a counterclockwise rotation so that actuator portion3390 abuts right end wall 3343. Further clockwise rotation of the S₂ camin the cutout 3302 from the FIG. 19B position to the FIG. 19A positioneffects the rearward shifting of output shift rail 3301. The shift iscompleted when the left locking notch-return portion 3342 contacts theleft corner 3345 of the cam follower surface 3309.

In the R1, R2, first and second speed ratios, the output rail is shiftedbefore the input rail as was done in the first and second embodiments.However, in the third through sixth speed ratios the input rail isshifted before the output rail. This demonstrates that the transmissioncontrol system of the present invention is flexible and can be modifiedto conform with transmissions of various configurations.

The shift control system 300 operates essentially as the control system100. In FIG. 18 the shift pattern of the shift control system of FIG. 17is illustrated. Neutral position 393 between the third and fourth speedratios corresponds with the position of the control shaft 328 in FIG.17. When the handle (not shown) of shift lever 384 is shifted to theright as viewed in FIG. 18 to the neutral position 394 between the fifthand sixth speed ratios, the control shaft moves one cam to the left asviewed in FIG. 17. Similarly when the handle of the shift lever is movedto the neutral position 392 between the first and second speed ratios,the control shaft 328 moves one cam to the right and moves yet anothercam to the right when the shift lever is moved to neutral position 391between the R1 and R2 speed ratios.

The third through sixth speeds may be considered to comprise thestandard "H" portion of the shift pattern shown in FIG. 18. The rightend of control shaft 328 is provided with a bore 351 that receives lightblockout spring 355 and associated parts. A heavy blockout spring 375and associated parts is received in the interior of interlock member 340to enable the operator to distinguish the additional speed ratios in anidentical fashion as the two pairs of leftward adjacent speed ratios aredistinguished in the first embodiment.

Except as noted all cams function as previously discussed with respectto the first embodiment. However, the shift rails are repositioned inthe transmission and the cams are rearranged on the control shaft 328 topresent the third embodiment six speed shift control system of thepresent invention. The selected cams are positioned in the cutouts ofrespective shift rails to provide the speed ratios as follows:

    ______________________________________                                        Speed    Input Shift Output Shift                                                                              Output Shift                                 Ratio    Rail 3307   Rail 3301   Rail 303                                     ______________________________________                                        R1-R2    O.sub.2 Cam 3368                                                                          Locking     F.sub.1 Cam 395                                                   Surface 366                                              1-2      O.sub.2 Cam 3372                                                                          Locking     R.sub.1 Cam 3383                                                  Surface 366                                              3-4      F.sub.1 Cam 3374                                                                          S.sub.2 Cam 381                                                                           Wide Inter-                                                                   locking                                                                       Member 340                                   5-6      R.sub.1 Cam 3336                                                                          S.sub.2 Cam 382                                                                           Wide Inter-                                                                   locking                                                                       Member 340                                   ______________________________________                                    

The Five Speed Transmission

Referring now to FIGS. 20-23, a fourth embodiment of the presentinvention is illustrated and is similar to the first embodiment of thecontrol system except as otherwise discussed below. Accordingly, likecomponents are denoted as in FIGS. 1-14 except that they are expressedin 400 Series notation.

In the fourth embodiment a transmission control system 400 for a fiveforward speed transmission is disclosed that has one reverse speed. Amultiple input-multiple output transmission for the control system ofthe fourth embodiment is not illustrated but known conventionaltransmissions could easily be adapted to cooperate with thistransmission control system.

The transmission control system 400 includes output shift rails 4401 and403 and input shift rail 407 having an auxiliary rail 4405 rigidlyattached thereto so that the auxiliary rail 4405 and input shift rail407 move in unison when a selected cam rotates in the cutout of inputshift rail 407 or the cutout of auxiliary rail 4405. It should be notedthat the cams are positioned on the control shaft 428 so that a cam isnot simultaneously positioned in the cutouts of input shift rail 407 andauxiliary rail 4405 during any of the speed ratios shown in FIG. 21. Thecutout for input shift rail 407 is similar to the cutout 108 of rail 107shown in the first embodiment. The cutout 4406 for auxiliary rail 4405is a modified version of the cutout 106 of the shift rail 105 in thatthe cutout is vertically reversed and the bottom portion is eliminated.The output shift rail 4401 has a generally circular cutout 4402 having atop cam follower portion 4409 as shown in FIG. 23.

FIG. 22A-E illustrates an F₂ cam utilized in this embodiment operatingin cutout 4406 of auxiliary rail 4405. FIG. 22C illustrates the positionof the F₂ cam when the control shaft 428 is in its neutral position. TheF₂ cam has top and bottom tooth portions 4463 which are inclined awayfrom left end wall portions 4411 of cutout 4405 when the control shaft428 and the F₂ cam mounted thereon is in its neutral FIG. 22C position.The movement of the F₂ cam from its FIG. 22C position to a FIG. 22Eposition is accomplished by moving the handle of the shift lever in adownward longitudinal direction as shown in FIG. 21 to cause clockwiserotation of the control shaft 428. Under clockwise rotation of thecontrol shaft 428, the bottom tooth portion 4463 comes into contact withthe bottom end wall 4411 of the cutout cam follower surface as shown inFIG. 22D and further clockwise rotation of the control shaft 428 willcause the auxiliary rail 4405 and shift rail 4407 connected thereto tomove in a forward input direction. In FIG. 22E the control shaft hasbeen rotated until the backside of upper tooth portion 4463 abuts toothlocking portion 4413 of the cutout 4406 and lower corner portion 4415 ofthe cam follower surface of the cutout 4406 is received in a lowernotch-return portion 4417.

To change speed ratios the F₂ cam is rotated counterclockwise from theFIG. 22E position so that the lower notch-return portion 4417 inabutment with the lower corner portion 4415 of the cam follower surfaceof the cutout 4406 will axially shift the auxiliary rail 4405 towardsthe rearward output direction of the transmission to return theauxiliary rail 4405 to its FIG. 22C neutral position, thus alsoreturning the shift rail 407 to its neutral position.

At this point the control shaft could be axially repositioned or furtherupward longitudinal movement of the shift lever 484 as shown in FIG. 21will effect additional counterclockwise rotation of the control shaft428 to cause the upper tooth portion of the F₂ cam to be placed inabutment with the upper end wall 4411 of the cam follower surface of thecutout 4406 and further counterclockwise rotation of the control shaft428 will cause auxiliary rail 4405 to shift in a rearward directionuntil the F₂ cam is in its FIG. 22A position wherein the backside oflower tooth portion 4463 is received in lower locking portion 4413 ofthe outer cam follower surface of cutout 4406 and the lower cornerportion 4415 is received in the lower notch-return portion 4417 of theF₂ cam. Similarly, downward movement of shift lever 484 to a neutralposition of the shift lever as shown in FIG. 21 will cause the F₂ cam toshift the auxiliary rail 4405 back to its neutral FIG. 22C position dueto the contact between notch-return portion 4417 and locking surface4413.

O₁ cam 4464 which is positioned in cutout 4402 of output shift rail 4401has a slight different configuration and is positioned in a differentlyconfigured cutout but operates in identical fashion as the O₁ cam in thefirst embodiment illustrated at FIG. 13.

In FIG. 21 the shift pattern of the shift control system 400 isillustrated. Neutral position 492 between the second and third speedratios corresponds with the position of control shaft 428 in FIG. 20.When the handle (not shown) of shift lever 484 is shifted to the rightas viewed in FIG. 21 to the neutral position between the fourth andfifth speed ratios, the control shaft moves one cam to the left thanthat viewed in FIG. 20. Similarly, when the handle of the shift lever ismoved to neutral position 491 between the reverse and first speed ratiosthe control shaft moves one cam to the right from that viewed in FIG.20.

As shown in FIG. 21 the second through fifth speeds may be considered tocomprise the standard "H" shift pattern. The right end of control shaft428 is provided with a bore 451 that receives light blockout spring 455and associated parts to enable the operator to sense the additionalfirst and reverse speed ratios in an identical fashion as the leftwardadjacent pair of speed ratios is sensed in the first embodiment.

Except as noted all cams function as previously discussed with respectto the first embodiment. However, the shift rails are repositioned inthe transmission and the cams are rearranged on the control shaft 428 topresent the fourth embodiment five speed shift control system of thepresent invention. The selected cams are positioned in the cutouts ofthe respective shift rails to provide the speed ratios as follows:

    ______________________________________                                                        Input Aux.                                                    Speed Auxiliary Shift Rail Output Shift                                                                           Output Shift                              Ratio Rail 4405 407        Rail 4401                                                                              Rail 403                                  ______________________________________                                        R-1   F.sub.2 Cam 482                                                                         --         O.sub.1 Cam 4464                                                                       Interlock                                                                     Member 4446                               2-3   --        O.sub.2 Cam 4468                                                                         Interlock                                                                              R.sub.1 Cam 4436                                                     Member 4438                                        4-5   --        O.sub.2 Cam 4472                                                                         Interlocking                                                                           F.sub.1 Cam 4474                                                     Member 481                                         ______________________________________                                    

From the foregoing, it is believed that those familiar with the art willreadily recognize and appreciate the novel concepts and features of thepresent invention. While the invention has been described in relation toonly four embodiments, numerous variations, changes and substitutions ofequivalence will present themselves to persons skilled in the art andmay be made without necessarily departing from the scope and principlesof this invention. As a result, the embodiments described herein aresubject to various modifications, changes and the like, with the scopeof this invention being determined solely by reference to the claimsappended hereto.

What is claimed is:
 1. A control for a transmission having multipleinput portions and multiple output portions in which a plurality ofspeed ratios are provided by actuating selected pairs of input andoutput portions, comprising:a pair of shift rails; an axially movableand rotatable control shaft; a pair of cam members mounted on thecontrol shaft so as to move and rotate therewith; each shift rail havinga cam follower surface; one of the cam members positioned on the controlshaft so that it is aligned with the cam follower surface of one of theshift rails when the other of the cam members is positioned to bealigned with the other of the shift rails; the one cam member adapted tocooperate with the cam follower surface of the one shift rail to effectmovement of the respective shift rail upon rotation of the control shaftin a chosen direction whereby one of the input portions is actuated; theother cam member adapted to cooperate with the cam follower surface ofthe other shift rail to effect movement of the respective shift railupon said rotation of the control shaft in a chosen direction wherebyone of the output portions is actuated; and the movement of the oneshift rail commences before and terminates during the movement of theother shift rail whereby the movements of the pair of shift rails areoverlapped during rotation of the control shaft.
 2. The transmissioncontrol as claimed in claim 1 wherein said one shift rail is the outputshift rail and said other shift rail is the input shift rail.
 3. Thetransmission control as claimed in claim 1 wherein said one shift railis the input shift rail and said other shift rail is the output shiftrail.
 4. The transmission control as claimed in claim 1 wherein eachshift rail has a cutout through which said control shaft extends andwherein the cam follower surface of each shift rail is provided on therespective cutout.
 5. A transmission control as in claim 1 wherein thereis a third shift rail having a cam follower surface, and said cammembers are arranged to effect movement only of any two of said threeshift rails.
 6. A transmission control as in claim 5 wherein saidcontrol shaft is provided with an interlocking member to preventmovement of the third shift rail when the other two move.
 7. Atransmission control as in claim 1 wherein there are two additionalshift rails each having a cam follower surface, and said cam members arearranged to effect movement only of any two of said four shift rails. 8.A transmission control as in claim 7 wherein said control shaft isprovided with two separate interlocking members to prevent movement ofthe third and fourth shift rails when the other two move.
 9. A methodfor moving shift rails in a transmission to effect speed ratio changescomprising the following steps:providing the transmission with arotatable control shaft; mounting first and second cam members on thecontrol shaft so as to rotate in unison with the control shaft;equipping a first rail with a first cam follower surface which isadapted to cooperate with said first cam member for operation of thefirst shift rail according to a predetermined first pattern when saidcontrol shaft is rotated through a selected arc, said first patternincluding an interval when it does not move; equipping a second railwith a second cam follower surface adapted to cooperate with said secondcam member for operation of the second shift rail according to apredetermined second pattern when said control shaft is rotated throughsaid selected arc, said second pattern including an interval when saidsecond rail moves and another interval when it does not move, said railmovement intervals overlapping whereby said two rails both move for onlya portion of said arc; and rotating said control shaft through said arc.10. The method as claimed in claim 9 further comprising providing eachshift rail with a cutout, having the respective cam follower surfacethereon, through which the control shaft extends.